Direct observation of inhomogeneous solid electrolyte interphase on MnO anode with atomic force microscopy and...

Area of Science:

• Materials Science
• Electrochemistry
• Battery Technology

Background:

• The solid electrolyte interphase (SEI) is a crucial passivation layer formed on electrodes in lithium ion batteries (LIBs).
• The mechanical properties of the SEI significantly influence the cycling performance and safety of LIBs.
• Quantitative investigation of SEI mechanical properties remains a significant challenge.

Purpose of the Study:

• To quantitatively determine the Young's modulus of SEI films formed on manganese oxide (MnO) anodes.
• To explore the inhomogeneous nature of SEI films in terms of morphology, structure, and mechanical characteristics.
• To develop and validate a novel quantitative methodology for SEI property investigation.

Main Methods:

• In situ mechanical testing of SEI films on MnO anodes.
• Microscopic and spectroscopic analysis to characterize SEI morphology and structure.
• Quantitative measurement of Young's modulus.

Main Results:

• The Young's modulus of SEI films on MnO anodes was quantitatively determined.
• Significant inhomogeneity in SEI morphology, structure, and mechanical properties was observed.
• The study provides new insights into the evolution of SEI during battery cycling.

Conclusions:

• The mechanical properties of SEI are critical for LIB performance and safety.
• SEI films exhibit inherent inhomogeneity that impacts their behavior.
• The established quantitative methodology offers a versatile approach for studying SEI in diverse electrode systems.